1. Field of Invention
The present invention relates to a scroll fluid machine such as a scroll vacuum pump or a scroll compressor.
2. Discussion of Related Art
U.S. Pat. No. 6,109,897A discloses a scroll fluid machine that comprises a fixed scroll and an orbiting scroll rotatably mounted to an eccentric axial portion of a driving shaft, a cooling path extending through the driving shaft axially, a cooling gas being introduced in the cooling path to cool bearings and sealing members between the orbiting scroll and the driving shaft.
However, in the scroll fluid machine, a cooling gas is sucked into and discharged from the cooling path by natural convection or stirring thereby making it impossible for the parts to be cooled effectively.